Voicemail error

Hello, whenever I am trying to access the voicemail, a new window pops up which says ‘Error performing request, unknown error’. When clicked on dismiss, it goes to the calling window where it shows calling voicemail and this window stays forever until we press the red disconnect button. Attaching the screenshots for your reference. Also, I bought this new iPhone from Flipkart last month and I haven’t set the password or haven’t registered for the voicemail either. Please help.